PC gamers like open world action games just like their console counterparts and that's pretty clear in Steam's latest weekly sales report. The list shows the Radical Entertainment-Activision game Prototype zoom to the top of Steam's sales list (based on revenue for the past seven days and ending on Sunday morning).

The rest of the list includes Railworks, the new train simulation title from RailSimulator.com, in the number 9 position. Also Tripwire Interactive's co-op shooter Killing Floor continues to make a killing; it's at number 3 on the list and has so far remained in the top five since it's release in mid-May